Steering control device

Abstract

To provide a steering control device capable of appropriately inspecting a steer-by-wire type steering device.SOLUTION: A steering control device controls the steering device of a vehicle. The steering device includes a steering mechanism that includes a reaction force motor. The steering control device includes a reaction force control device 1A. The reaction force control device 1A controls the reaction force motor based on a torque command value calculated in accordance with the steered state of a steering wheel. The reaction force control device 1A has, as control modes for controlling the reaction force motor, a normal mode for causing the vehicle to run, and an inspection mode for inspecting the steering mechanism. The reaction force control device 1A calculates a running torque command value that is a suitable torque command value for the vehicle to run when the control mode is in the normal mode. The running torque command value is a reaction force torque command value T*. When the control mode is in the inspection mode, the reaction force control device 1A calculates a final inspection torque command value Ttest* that is a suitable torque command value for inspection.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a steering control device. [Background technology]

[0002] Conventionally, brushless motors have been used as the drive source for electric power steering devices. Brushless motors undergo various inspections before being incorporated into electric power steering devices. For example, Patent Document 1 describes a method for inspecting whether the cogging torque of a brushless motor is within an allowable range. The inspection is performed while rotating the rotor of the brushless motor using a drive source motor of an inspection device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-042137 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the development of so-called steer-by-wire steering systems, which separate the power transmission between the steering wheel and the steered wheels, has progressed. Steer-by-wire steering systems also need to be properly inspected. [Means for solving the problem]

[0005] A steering control device that can solve the above problem is configured to control a steering device in which power transmission between the steered wheels of a vehicle and the steering wheel is separated. The steering device has a steering mechanism including a reaction motor configured to generate a steering reaction force to be applied to the steering wheel. The steering control device has a reaction force control unit configured to control the reaction motor based on a torque command value calculated in accordance with the steering state of the steering wheel. The reaction force control unit has, as control modes for controlling the reaction motor, a normal mode for driving the vehicle and an inspection mode for inspecting the steering mechanism. When the control mode is the normal mode, the reaction force control unit is configured to calculate, as the torque command value, a driving torque command value suitable for driving the vehicle, and when the control mode is the inspection mode, to calculate, as the torque command value, an inspection torque command value suitable for the inspection.

[0006] According to this configuration, when the control mode is the inspection mode, an inspection torque command value suitable for inspection is calculated as the torque command value, thereby making it possible to inspect the steering mechanism appropriately.

[0007] In the above steering control device, the inspection may include a first inspection and a second inspection. In this case, the reaction force control unit may be configured to calculate a first inspection torque command value suitable for the first inspection as the inspection torque command value when the first inspection is performed, and to use a second inspection torque command value suitable for the second inspection as the inspection torque command value when the second inspection is performed.

[0008] According to this configuration, when the first inspection is performed, a first inspection torque command value suitable for the first inspection is calculated as the inspection torque command value. Also, when the second inspection is performed, a second inspection torque command value suitable for the second inspection is calculated as the inspection torque command value. Therefore, the first inspection and the second inspection of the steering mechanism can be performed appropriately.

[0009] In the above steering control device, the inspection may include a proportional load inspection by energizing the steering mechanism to check the operability or input / output characteristics of the steering mechanism. The reaction force control unit may be configured to perform the following operations: a dead-band processing for replacing a steering torque value detected by an on-board torque sensor with zero when the steering torque value is within a dead-band range; a processing for calculating an assist torque command value, which is a torque in the same direction as the steering direction of the steering wheel, based on the steering torque after the dead-band processing; a processing for calculating an axial force acting on a steering shaft that steers the turnable wheels based on a steering state of the turnable wheels and converting the calculated axial force into a torque applied to the steering wheel to calculate an axial force torque; and a processing for calculating the torque command value by subtracting the axial force torque from the assist torque command value. Furthermore, when the control mode is the inspection mode, the reaction force control unit may be configured to use the assist torque command value calculated based on the steering torque before the dead-band processing as the inspection torque command value.

[0010] According to this configuration, a proportional load test of the steering mechanism can be appropriately performed, just as in the case where the steering device is an electric power steering device. In the above steering control device, the inspection may include a torque fluctuation inspection for checking whether torque fluctuation of the reaction motor when current is applied to the steering mechanism and torque is applied to the steering shaft is within an allowable range. The reaction force control unit may be configured to perform a dead-band process for replacing a value of the steering torque detected by an on-board torque sensor with zero when the value of the steering torque is within a dead-band range, a process for calculating an assist torque command value that is a torque in the same direction as the steering direction of the steering wheel based on the steering torque after the dead-band process, a process for calculating an axial force acting on a turning shaft that steers the turnable wheels based on a steering state of the turnable wheels and converting the calculated axial force into a torque with respect to the steering wheel to calculate an axial force torque, and a process for calculating the torque command value by subtracting the axial force torque from the assist torque command value. The axial force may include a hysteresis compensation amount calculated based on a steering angle of the steering wheel, and the hysteresis compensation amount may be an axial force for compensating for hysteresis characteristics due to friction of the steered wheels. In this case, when the control mode is the inspection mode, the reaction force control unit may be configured to convert the hysteresis compensation amount into a torque on the steering shaft to calculate an inspection axial force torque, and to calculate the inspection torque command value by subtracting the inspection axial force torque from the assist torque command value.

[0011] According to this configuration, the torque fluctuation inspection of the steering mechanism can be carried out appropriately, just as in the case where the steering device is an electric power steering device. In the steering control device, the reaction force control unit may be configured to calculate the inspection axial force torque by converting a value obtained by multiplying the hysteresis compensation amount by an adjustment gain into a torque applied to the steering shaft. The adjustment gain may be a fixed value that is set from the viewpoint of appropriately performing the torque fluctuation inspection.

[0012] According to this configuration, the torque fluctuation inspection of the steering mechanism can be performed more appropriately, as in the case where the steering device is an electric power steering device. In the above steering control device, the reaction force control unit may be configured to switch the control mode from the normal mode to the inspection mode upon receiving an external command.

[0013] According to this configuration, the control mode can be easily switched from the normal mode to the inspection mode by an external command. [Effects of the Invention]

[0014] According to the steering control device of the present invention, it is possible to appropriately test a steer-by-wire type steering device. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a configuration diagram of a steering device in which an embodiment of a steering control device is installed. [Figure 2] FIG. 1 is a block diagram of a reaction force control device and a steering control device according to an embodiment. [Figure 3] FIG. 2 is a block diagram of a reaction torque command value calculation unit according to an embodiment. [Figure 4] FIG. 2 is a block diagram of an assist torque command value calculation unit according to one embodiment. [Figure 5] FIG. 2 is a block diagram of an axial force calculation unit according to one embodiment. [Figure 6] 1 is a front view showing a configuration of an inspection device according to an embodiment; [Figure 7] FIG. 2 is a block diagram of a test circuit according to an embodiment. [Figure 8] FIG. 2 is a block diagram of a test circuit according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of the steering control device 1 will be described below. As shown in FIG. 1, the control object of steering control device 1 is a steer-by-wire steering device 2. Steering device 2 has a steering mechanism 3 and a steering mechanism 4. Steering mechanism 3 is a mechanical part that is steered by a driver via steering wheel 5. Steering mechanism 4 is a mechanical part that steers steerable wheels 6 of a vehicle in response to steering of steering wheel 5. Steering control device 1 includes a reaction force control device 1A and a steering control device 1B. The control object of reaction force control device 1A is the steering mechanism 3. Reaction force control device 1A performs reaction force control. Reaction force control device 1A corresponds to a reaction force control section. The control object of steering control device 1B is the steering mechanism 4. Steering control device 1B performs steering control. Steering control device 1B corresponds to a steering control section.

[0017] The steering mechanism 3 has a steering shaft 11, a reaction motor 12, and a reducer 13. The steering wheel 5 is connected to the steering shaft 11 so as to be rotatable integrally therewith. The reaction motor 12 is a source of a steering reaction force applied to the steering shaft 11. The steering reaction force is a force in the opposite direction to the steering direction of the steering wheel 5. The reaction motor 12 is, for example, a three-phase brushless motor. The reducer 13 decelerates the rotation of the reaction motor 12 and transmits the decelerated rotation to the steering shaft 11.

[0018] The steering mechanism 4 has a pinion shaft 21, a steered shaft 22, and a housing 23. The housing 23 rotatably supports the pinion shaft 21. The housing 23 also accommodates the steered shaft 22 so that it can reciprocate. Power transmission between the steered shaft 22 and the steering wheel 5 is separated. The pinion shaft 21 is arranged to intersect with the steered shaft 22. Pinion teeth 21a of the pinion shaft 21 mesh with rack teeth 22a of the steered shaft 22. Tie rods 25 are connected to both ends of the steered shaft 22 via rack ends 24 made up of ball joints. The ends of the tie rods 25 are connected to a knuckle (not shown) to which the steered wheels 6 are assembled.

[0019] The steering mechanism 4 comprises a steering motor 31, a transmission mechanism 32, and a conversion mechanism 33. The steering motor 31 is a source of the steering force applied to the steering shaft 22. The steering force is a force for steering the steered wheels 6. The steering motor 31 is, for example, a three-phase brushless motor. The transmission mechanism 32 is, for example, a belt transmission mechanism. The transmission mechanism 32 transmits the rotation of the steering motor 31 to the conversion mechanism 33. The conversion mechanism 33 is, for example, a ball screw mechanism. The conversion mechanism 33 converts the rotation transmitted via the transmission mechanism 32 into axial movement of the steering shaft 22.

[0020] The steered shaft 22 moves in the axial direction, and the steered angle θ of the steered wheels 6 w The pinion teeth 21a of the pinion shaft 21 are engaged with the rack teeth 22a of the steered shaft 22, and therefore rotate in conjunction with the movement of the steered shaft 22. The pinion shaft 21 is a shaft that rotates in conjunction with the steering operation of the steered wheels 6.

[0021] The reaction force control device 1A controls the operation of the reaction force motor 12. The reaction force control device 1A has a processing circuit including any one of the following three components A1, A2, and A3. A1. One or more processors that operate according to a computer program, which is software. The processor includes a CPU (central processing unit) and memory.

[0022] A2. One or more dedicated hardware circuits, such as an application specific integrated circuit (ASIC), that perform at least some of the processing. The ASIC includes a CPU and memory.

[0023] A3. A hardware circuit that combines configurations A1 and A2. The memory is a computer-readable medium that stores a program that describes processes or instructions for the computer. In this embodiment, the computer is a CPU. The memory includes RAM (random access memory) and ROM (read only memory). The CPU executes the program stored in the memory at a predetermined calculation cycle to perform various controls.

[0024] The reaction force control device 1A receives detection results from sensors mounted on the vehicle, including a vehicle speed sensor 41, a torque sensor 42, and a rotation angle sensor 43. The vehicle speed sensor 41 detects the vehicle speed V. The vehicle speed V is a state variable that reflects the traveling state of the vehicle. The torque sensor 42 is provided on the steering shaft 11. The torque sensor 42 is located on the steering wheel 5 side of the connecting portion of the steering shaft 11 with the reducer 13. The torque sensor 42 detects the steering torque T applied to the steering shaft 11. h Detects the steering torque T h is calculated based on the amount of twist of the torsion bar 42a provided on the steering shaft 11. h is a state variable that reflects the steering state of the steering wheel 5. The rotation angle sensor 43 is provided in the reaction force motor 12. The rotation angle sensor 43 detects the rotation angle θ of the reaction force motor 12. a Detect.

[0025] Steering torque T h , and the rotation angle θ of the reaction force motor 12 a is, for example, a positive value when the steering wheel 5 is steered to the right, and is a negative value when the steering wheel 5 is steered to the left.

[0026] The reaction force control device 1A controls the operation of the reaction force motor 12 using the detection results of the vehicle speed sensor 41, the torque sensor 42, and the rotation angle sensor 43. The reaction force control device 1A controls the operation of the reaction force motor 12 using the detection results of the steering torque T hThe power supply to the reaction force motor 12 is controlled so that the reaction force motor 12 generates a steering reaction force corresponding to the steering reaction force.

[0027] The steering control device 1B controls the operation of the steering motor 31. Like the reaction force control device 1A, the steering control device 1B has a processing circuit including any one of the three components A1, A2, A3 described above.

[0028] The steering control device 1B takes in the detection results of sensors mounted on the vehicle. The sensors include a rotation angle sensor 44. The rotation angle sensor 44 is provided in the steering motor 31. The rotation angle sensor 44 detects a rotation angle θ of the steering motor 31. b The rotation angle θ of the steering motor 31 is detected. b is, for example, a positive value when the steering wheel 5 is steered to the right, and is a negative value when the steering wheel 5 is steered to the left.

[0029] The steering control device 1B uses the detection result of the rotation angle sensor 44 to control the operation of the steering motor 31. The steering control device 1B controls the supply of power to the steering motor 31 so that the steered wheels 6 are turned in accordance with the steering state of the steering wheel 5.

[0030] <Configuration of reaction force control device 1A> Next, the configuration of the reaction force control device 1A will be described. As shown in FIG. 2, the reaction force control device 1A includes a steering angle calculation unit 51, a reaction force torque command value calculation unit 52, and an energization control unit 53.

[0031] The steering angle calculation unit 51 calculates the rotation angle θ of the reaction force motor 12 detected through the rotation angle sensor 43. a Based on this, the steering angle θ of the steering wheel 5 s Calculate the steering angle θ s is the rotation angle of the steering wheel 5 relative to the neutral position of the steering wheel 5. The neutral position is the rotation position of the steering wheel 5 that corresponds to the straight-ahead state of the vehicle.

[0032] The reaction torque command value calculation unit 52 calculates the steering torque T h and the reaction torque command value T based on the vehicle speed V * Calculate the reaction torque command value T * is the target value of the steering reaction force to be generated by the reaction force motor 12. The steering reaction force is a torque in the direction opposite to the steering direction of the steering wheel 5. The steering torque T h The larger the absolute value of and the slower the vehicle speed V, the greater the reaction torque command value T * The absolute value of is larger.

[0033] The power supply control unit 53 determines the reaction torque command value T * Specifically, the power supply control unit 53 supplies the reaction force motor 12 with power according to the reaction force torque command value T * The current control unit 53 calculates a current command value for the reaction force motor 12 based on the current I generated in the power supply path through a current sensor 54 provided in the power supply path for the reaction force motor 12. a Detect the value of the current I a The value of is the value of the current supplied to the reaction motor 12. The current control unit 53 calculates the current command value and the current I a The deviation from the value of the reaction torque command value T is calculated, and the power supply to the reaction motor 12 is controlled so as to eliminate the deviation. * A torque corresponding to the

[0034] <Configuration of steering control device 1B> Next, the configuration of the steering control device 1B will be described. As shown in FIG. 2, the steering control device 1B has a pinion angle calculation unit 61, a target pinion angle calculation unit 62, a pinion angle feedback control unit 63, and an energization control unit 64.

[0035] The pinion angle calculation unit 61 calculates the rotation angle θ of the steering motor 31 detected through the rotation angle sensor 43. b Based on this, the pinion angle θ p Calculate the pinion angle θ pis the rotation angle of pinion shaft 21, and corresponds to the actual angle, which is the actual angle of pinion shaft 21. Steering motor 31 and pinion shaft 21 are linked via transmission mechanism 32, conversion mechanism 33, and steering shaft 22. Therefore, the rotation angle θ of steering motor 31 b and pinion angle θ p By utilizing this correlation, the rotation angle θ of the steering motor 31 is b From pinion angle θ p The pinion shaft 21 is meshed with the steering shaft 22. Therefore, the pinion angle θ p There is also a correlation between the pinion angle θ and the amount of movement of the steering shaft 22. p is the steering angle θ of the steered wheels 6 w , that is, a state variable that reflects the steering state of the steered wheels 6.

[0036] The target pinion angle calculation unit 62 calculates the steering angle θ calculated by the steering angle calculation unit 51. s Based on the target pinion angle θ p * Calculate the target pinion angle θ p * is the pinion angle θ p The target pinion angle calculation unit 62 calculates the target pinion angle θ so as to realize a steering angle ratio set according to product specifications, etc. p * The steering angle ratio is calculated by the steering angle θ s steering angle θ w is the ratio of

[0037] The target pinion angle calculation unit 62 sets a steering angle ratio according to the vehicle running state, such as the vehicle speed V, and calculates the target pinion angle θ according to the set steering angle ratio. p * As the vehicle speed V decreases, the target pinion angle calculation unit 62 calculates the steering angle θ s steering angle θ w The target pinion angle θ p * As the vehicle speed V increases, the target pinion angle calculation unit 62 calculates the steering angle θs steering angle θ w The target pinion angle θ p * The target pinion angle calculation unit 62 calculates the steering angle θ s The correction angle for the steering angle θ is calculated. s By adding to the target pinion angle θ according to the steering angle ratio p * Calculate the following.

[0038] Depending on the product specifications, the target pinion angle calculation unit 62 may calculate the target pinion angle θ so that the steering angle ratio becomes "1:1" regardless of the running state of the vehicle. p * The following may be calculated.

[0039] The pinion angle feedback control unit 63 receives the target pinion angle θ calculated by the target pinion angle calculation unit 62. p * , and the pinion angle θ calculated by the pinion angle calculation unit 61 p The pinion angle feedback control unit 63 receives the pinion angle θ p is the target pinion angle θ p * The pinion angle θ p Through the feedback control of the steering torque command value T p * Calculate the steering torque command value T p * is a command value for the torque generated by the steering motor 31, and is a target value of the steering force.

[0040] The power supply control unit 64 controls the steering torque command value T p * Specifically, the power supply control unit 64 supplies the steering motor 31 with electric power according to the steering torque command value T p *The current control unit 64 calculates a current command value for the steering motor 31 based on the current I generated in the power supply path through a current sensor 65 provided in the power supply path for the steering motor 31. b Detect the value of the current I b The value of is the value of the current supplied to the steering motor 31. The current control unit 64 calculates the current command value and the current I b The deviation from the value of the steering torque command value T is calculated and the power supply to the steering motor 31 is controlled so as to eliminate the deviation. p * A torque corresponding to the

[0041] <Configuration of reaction torque command value calculation unit 52> Next, the configuration of the reaction torque command value calculation unit 52 will be described in detail. As shown in FIG. 3, the reaction torque command value calculation unit 52 includes a dead band processing unit 80, an assist torque command value calculation unit 81, an axial force calculation unit 82, and a subtractor 83.

[0042] The dead zone processing unit 80 detects the steering torque T h The dead zone processing unit 80 takes in the steering torque T h That is, the dead zone processing unit 80 performs dead zone processing for the steering torque T h If the value of is within a predetermined dead zone, the steering torque T h The value of the dead zone is replaced with "0" and output. The upper and lower limits of the dead zone are set, for example, according to the product specifications. The steering torque T h is the steering torque T after dead zone processing h1 After dead zone processing, the steering torque T h1 is the reaction torque command value T * The final steering torque T used to calculate h is.

[0043] The assist torque command value calculation unit 81 calculates the steering torque T after the dead zone processing from the dead zone processing unit 80. h1, and the vehicle speed V detected by the vehicle speed sensor 41. The assist torque command value calculation unit 81 calculates the steering torque T h1 and vehicle speed V, an assist torque command value T1 is calculated. The assist torque command value T1 corresponds to the target value of the assist torque when the steering device 2 is an electric power steering device. The assist torque is a force for assisting the steering of the steering wheel 5. The assist torque command value T1 is a torque in the same direction as the steering direction of the steering wheel 5. The post-dead-zone processing steering torque T h1 The larger the absolute value of the assist torque command value T1 is and the slower the vehicle speed V is, the larger the absolute value of the assist torque command value T1 is.

[0044] The axial force calculation unit 82 calculates the pinion angle θ calculated by the pinion angle calculation unit 61. p , the current I of the steering motor 31 detected through the current sensor 65 b , the vehicle speed V detected by the vehicle speed sensor 41, and the steering angle θ calculated by the steering angle calculation unit 51. s The axial force calculation unit 82 takes in the pinion angle θ p , the current I of the steering motor 31 b value, vehicle speed V, and steering angle θ s Based on this, the axial force acting on the steered shaft 22 is calculated. The axial force calculation unit 82 converts the calculated axial force into a torque applied to the steering shaft 11, thereby calculating the axial force torque T2.

[0045] The subtractor 83 takes in the assist torque command value T1 calculated by the assist torque command value calculation unit 81 and the axial force torque T2 calculated by the axial force calculation unit 82. The subtractor 83 subtracts the axial force torque T2 from the assist torque command value T1 to obtain the reaction torque command value T * Calculate the following.

[0046] <Configuration of assist torque command value calculation unit 81> Next, the configuration of the assist torque command value calculation unit 81 will be described in detail. As shown in FIG. 4, the assist torque command value calculation unit 81 includes a basic control unit 81A, a compensation control unit 81B, and an adder 81C.

[0047] The basic control unit 81A controls the steering torque T h and vehicle speed V. The basic assist torque T11 is calculated based on the steering torque T h The basic assist torque T11 is a torque that serves as a basis for generating a steering reaction force of an appropriate magnitude according to the vehicle speed V. The basic assist torque T11 is also a torque that serves as a basis for calculating the assist torque command value T1.

[0048] The compensation control unit 81B executes compensation control to achieve a better steering feel. The compensation control includes, for example, stabilization control, steering wheel return control, and damping control. The stabilization control is control to stabilize the system by suppressing resonance characteristics. The steering wheel return control is control to compensate for the return characteristics of the steering wheel 5. The damping control is control to compensate for the viscosity of the steering device 2.

[0049] The compensation control unit 81B calculates the compensation torque T12 based on the vehicle state. The vehicle state includes the running state of the vehicle or the steering state of the steering wheel 5. The compensation torque T12 includes, for example, a stabilization torque, a steering wheel returning torque, and a damping torque.

[0050] The stabilizing torque is a torque for stabilizing the system by suppressing the resonance characteristics, and is the steering torque T h and the vehicle speed V. The steering wheel return torque is a torque for compensating for the return characteristics of the steering wheel 5, and is calculated based on the steering torque T h , vehicle speed V, steering angle θ s and the steering angular velocity. The steering angular velocity is calculated based on the steering angle θ sThe damping torque is obtained by differentiating with respect to time. The damping torque is a torque for compensating for the viscosity of the steering device 2, and is calculated to suppress the steering angular velocity of the steering wheel 5. The damping torque is calculated based on the steering angular velocity and the vehicle speed V.

[0051] The adder 81C calculates the assist torque command value T1 by adding the basic assist torque T11 and the compensation torque T12. <Configuration of axial force calculation unit 82> Next, the configuration of the axial force calculation unit 82 will be described in detail.

[0052] As shown in FIG. 5, the axial force calculation section 82 has an angle axial force calculation section 82A, a current axial force calculation section 82B, a mixed axial force calculation section 82C, and a converter 82D. The angle axial force calculation unit 82A calculates the pinion angle θ p The angular axial force AF1 is calculated based on the pinion angle θ p is a state variable that reflects the steering state of the steered wheels 6. The angular axial force AF1 is p The larger the absolute value of AF1 becomes and the slower the vehicle speed V becomes, the larger the absolute value is set. p The angular axial force AF1 is an axial force that does not reflect the road surface condition or the force acting on the steering shaft 22.

[0053] The angle axial force calculation unit 82A calculates the pinion angle θ p The basic angular axial force is calculated based on the pinion angle θ. The basic angular axial force is the axial force that is the basis for calculating the angular axial force AF1. The absolute value of the basic angular axial force is calculated based on the pinion angle θ p The larger the absolute value of the steering angle θ calculated by the steering angle calculation unit 51, the larger the angle axial force calculation unit 82A. s The hysteresis compensation amount is an axial force for compensating for the hysteresis characteristics due to friction of the steered wheels 6 when the steered wheels 6 are turned. The absolute value of the hysteresis compensation amount is calculated based on the steering angle θ sThe larger the change in the absolute value of the steering angle θ s As the change in the absolute value of increases, the steering angle θ s The slope, which is the ratio of the change in the absolute value of the hysteresis compensation amount to the change in the absolute value of the steering angle θ, gradually decreases and eventually becomes constant. The angle axial force calculation unit 82A may change the hysteresis compensation amount in accordance with the vehicle speed V. The angle axial force calculation unit 82A calculates the angle axial force AF1 by adding the basic angle axial force and the hysteresis compensation amount. The angle axial force AF1 is calculated by the following equation: s It has hysteresis characteristics with respect to changes in

[0054] The current axial force calculation unit 82B calculates the current I b The current axial force AF2 is calculated based on the value of the current I of the steering motor 31. b The value of is a state variable that reflects the steering state of the steered wheels 6. The current I of the steering motor 31 b The value of the target pinion angle θ p * and the actual pinion angle θ p That is, the current I of the steering motor 31 changes depending on the difference between the b The value of the current I of the steering motor 31 reflects the actual road surface condition acting on the steering wheels 6. b The current axial force calculation unit 82B calculates an axial force that reflects the influence of the road surface condition based on the value of the current I of the steering motor 31. The current axial force calculation unit 82B calculates a gain, which is a coefficient corresponding to the vehicle speed V, based on the value of the current I of the steering motor 31. b The current axial force AF2 is calculated by multiplying the value of the current axial force AF2 by the road surface condition or the force acting on the steered shaft 22 via the steered wheels 6.

[0055] The mixed axial force calculation unit 82C receives the angular axial force AF1 calculated by the angular axial force calculation unit 82A and the current axial force AF2 calculated by the current axial force calculation unit 82B. The mixed axial force calculation unit 82C calculates a mixed axial force AF3 using the angular axial force AF1 and the current axial force AF2. The mixed axial force AF3 is an axial force obtained by mixing the angular axial force AF1 and the current axial force AF2 at a predetermined distribution ratio. The mixed axial force calculation unit 82C sets a first distribution ratio DR1 and a second distribution ratio DR2 according to various state variables that reflect the vehicle state. The first distribution ratio DR1 is a distribution ratio that is set individually for the angular axial force AF1. The second distribution ratio DR2 is a distribution ratio that is set individually for the current axial force AF2. The vehicle state includes vehicle behavior, road surface conditions, and steering conditions.

[0056] The mixed axial force calculation unit 82C sets the values ​​of the first allocation ratio DR1 and the second allocation ratio DR2 in the range of "0 (0%)" to "1 (100%)" in increments of, for example, "0.1" based on product specifications, etc. However, the mixed axial force calculation unit 82C sets the values ​​of the first allocation ratio DR1 and the second allocation ratio DR2 so that the sum of the value of the first allocation ratio DR1 and the value of the second allocation ratio DR2 is "1." The first allocation ratio DR1 indicates the degree to which the angle axial force AF1 is reflected in the mixed axial force AF3. The second allocation ratio DR2 indicates the degree to which the current axial force AF2 is reflected in the mixed axial force AF3.

[0057] The mixed axial force calculation unit 82C calculates the mixed axial force AF3 by adding together the value obtained by multiplying the angle axial force AF1 by the first distribution ratio DR1, which is set individually, and the value obtained by multiplying the current axial force AF2 by the second distribution ratio DR2, which is set individually. The mixed axial force is expressed by the following equation (1).

[0058] AF3 = AF1 · DR1 + AF2 · DR2 ... (1) The converter 82D converts the mixed axial force AF3 calculated by the mixed axial force calculation unit 82C into a torque to the steering wheel 5, thereby calculating the axial force torque T2.

[0059] <Inspection of Steering Device 2> The steering device 2 undergoes various tests during the inspection process. The tests include tests of the steering mechanism 3 and the turning mechanism 4. For example, the test of the steering mechanism 3 includes a first test and a second test. The first test is a proportional load test. The proportional load test is a test in which current is actually applied to the steering mechanism 3 to check the operability or input / output characteristics of the steering mechanism 3. The second test is a torque fluctuation test. The torque fluctuation test is a test in which current is actually applied to the steering mechanism 3 to check whether the torque fluctuation of the reaction motor 12 is within an allowable range when a predetermined torque is applied to the steering shaft 11.

[0060] As shown in FIG. 6, the steering mechanism 3 is inspected using an inspection device 90. The inspection is performed without the steering wheel 5 attached to the steering shaft 11. Although not shown in FIG. 1, the steering mechanism 3 has a steering column 14. The steering column 14 is a cylindrical body with a circular cross section, and rotatably supports the steering shaft 11. The steering shaft 11 passes through the steering column 14 in the axial direction. The reaction force control device 1A is provided, for example, at the end of the reaction force motor 12. The steering mechanisms 3 to be inspected are replaced one after another and attached to the inspection device 90.

[0061] The inspection device 90 includes a base 91 , first to third support frames 92 to 94 , an inspection motor 95 , a torque meter 96 , and a controller 97 . The base 91 is, for example, in the shape of a flat plate and is placed on an installation surface. The first to third support frames 92 to 94 are provided on the base 91. The first to third support frames 92 to 94 are spaced apart from one another. The second support frame 93 is disposed between the first support frame 92 and the third support frame 94.

[0062] The first support frame 92 rotatably supports a first end of the steering shaft 11. The first end is the end of the steering shaft 11 to which the steering wheel 5 is connected. The second support frame 93 supports the steering column 14. The third support frame 94 supports the inspection motor 95.

[0063] The inspection motor 95 has an output shaft 95A. A second end of the steering shaft 11 is connected to the output shaft 95A via a coupling, for example, so as to be rotatable integrally with the output shaft 95A. The second end is an end opposite to the first end of the steering shaft 11. The steering shaft 11 is disposed coaxially with the output shaft 95A.

[0064] The torque meter 96 is provided on the output shaft 95A. The torque meter 96 measures the torque T applied to the output shaft 95A and, in turn, to the steering shaft 11. t The torque generated by the inspection motor 95 and the torque generated by the reaction motor 12 are applied to the steering shaft 11.

[0065] The controller 97 has an examination selection switch. The controller 97 performs an examination selected by the examination selection switch. The examination includes the first examination and the second examination.

[0066] The controller 97 has a start switch. When the start switch is turned on, the controller 97 controls the driving of the inspection motor 95 so that the inspection motor 95 generates a predetermined torque. The controller 97 detects the torque T detected by the torque meter 96 while the inspection motor 95 is being driven. t is temporarily stored in memory.

[0067] When the start switch is turned on, the controller 97 outputs code S c Set the value of Code S cis a command to the reaction force control device 1A of the steering control device 1. When the start switch is turned on, the controller 97 also controls the vehicle speed V and the target pinion angle θ used by the reaction force control device 1A. p * Specify the vehicle speed V and target pinion angle θ. p * The values ​​of are all "0".

[0068] The reaction force control device 1A is code S c The control mode of the reaction motor 12 is switched based on the value of . The control mode is a control method of the reaction motor 12 by the reaction force control device 1A. The control modes include a normal mode and an inspection mode. The normal mode is a control mode of the reaction motor 12 when no inspection of the steering mechanism 3 is performed, i.e., when the vehicle is running. The inspection mode is a control mode of the reaction motor 12 when inspection of the steering mechanism 3 is performed. The inspection modes further include a first inspection mode and a second inspection mode. The first inspection mode is a control mode of the reaction motor 12 when the previous first inspection is performed. The second inspection mode is a control mode of the reaction motor 12 when the previous second inspection is performed.

[0069] When the start switch is turned on while the first test is selected by the test selection switch, the controller 97 outputs code S c Set the value of "01". In this case, code S c serves as an electrical signal indicating the start of the first inspection of the steering mechanism 3. Also, the code S c is a command to the reaction force control device 1A, which requests that the control mode of the reaction force motor 12 be switched to the first inspection mode.

[0070] When the start switch is turned on while the second test is selected by the test selection switch, the controller 97 outputs code S c Set the value of "02". In this case, code S c serves as an electrical signal indicating the start of the second inspection of the steering mechanism 3. Also, the code Sc is a command to the reaction force control device 1A, which requests that the control mode of the reaction force motor 12 be switched to the second inspection mode.

[0071] When the start switch is turned off while the first or second test is being performed, the controller 97 outputs a code S c Set the value of code S to "00". c The code S functions as an electrical signal indicating that the first inspection or the second inspection of the steering mechanism 3 has been completed. c is a command to the reaction force control device 1A, which requests that the control mode of the reaction force motor 12 be switched to the normal mode.

[0072] The controller 97 has an analysis switch. When the analysis switch is turned on, the controller 97 analyzes the torque T t The controller 97 performs frequency analysis on the signal, and determines the test results based on the analysis data obtained by the frequency analysis. The test results are the results of the test selected by the test selection switch. The controller 97 has a monitor. The controller 97 displays the analysis data and the test results on the monitor.

[0073] <Test circuit> Next, the inspection circuit will be described. The reaction force control device 1A has a test circuit for properly testing the steering mechanism 3. The test circuit calculates a torque command value for the reaction force motor 12 as a reaction force torque command value T * and the test torque command value. * is the torque command value during non-inspection, which is the torque command value for driving when the vehicle is running. The torque command value for inspection is the torque command value during inspection. The inspection circuit is used when the first inspection or the second inspection is performed. The first inspection is a proportional load inspection. The second inspection is a torque fluctuation inspection.

[0074] As shown in FIG. 7, the inspection circuit has a first switch 101. The first switch 101 is provided in the reaction torque command value calculation unit 52 of the reaction force control device 1A. The first switch 101 is disposed on a calculation path between the dead band processing unit 80 and the assist torque command value calculation unit 81. The first switch 101 receives as data input the post-dead band processing steering torque T h1 and the steering torque T detected through the torque sensor 42. h The steering torque T during the test is taken into account. h is equal to the torque generated by the inspection motor 95. The first switch 101 also receives a code S set by the controller 97 as a control input. c Take the value of

[0075] The first switch 101 has code S c Based on the value of h1 and the steering torque T before dead zone processing h Either of these is used as the final steering torque T h2 Final steering torque T h2 is the final steering torque used to calculate the assist torque command value T1. Code S c If the value of is "01", the first switch 101 detects the steering torque T h The final steering torque T h2 Select as Code S c If the value of is "02" or "00", the first switch 101 switches the steering torque T after the dead zone processing. h1 The final steering torque T h2 The assist torque command value calculation unit 81 selects the final steering torque T h2 and the vehicle speed V, an assist torque command value T1 is calculated.

[0076] 8, the inspection circuit has a multiplier 102, a converter 103, a subtractor 104, a second switch 105, and a third switch 106. The multiplier 102, the converter 103, the subtractor 104, the second switch 105, and the third switch 106 are arranged on a calculation path between the reaction force torque command value calculation unit 52 and the energization control unit 53 in the reaction force control device 1A.

[0077] The multiplier 102 multiplies the hysteresis compensation amount F calculated by the angle axial force calculation unit 82A by hys and adjustment gain G a Adjustment gain G a is a coefficient set from the viewpoint of properly performing the second inspection, and is used to calculate the inspection axial force required for the second inspection. hys The inspection axial force is a virtual axial force required for the second inspection. Adjustment gain G a is a fixed value determined by product specifications such as the length of the steered shaft 22 and the specific stroke. The specific stroke is the amount of movement of the steered shaft 22 per one rotation of the pinion shaft 21. Adjustment gain G a is stored in the memory. The multiplier 102 multiplies the hysteresis compensation amount F hys Adjust the gain G a By multiplying this, the test axial force F test Calculate the following.

[0078] The converter 103 converts the inspection axial force F calculated by the multiplier 102 into test The converter 103 takes in the inspection axial force F test is converted into a torque for the steering shaft 11, the inspection axial torque T2 test Calculate the inspection axial torque T2 test is the virtual axial torque required for the second test.

[0079] The subtractor 104 subtracts the assist torque command value T1 calculated by the assist torque command value calculation unit 81 and the inspection axial force torque T2 calculated by the converter 103. testThe subtractor 104 subtracts the inspection axial force torque T2 from the assist torque command value T1. test The second torque command value for inspection T test2 * Calculate the following.

[0080] The second switch 105 receives the assist torque command value T1 calculated by the assist torque command value calculation unit 81 as a data input and converts it into the first inspection torque command value T test1 * The second switch 105 receives as data input the second torque command value for inspection T test2 * The second switch 105 also receives as its control input the code S set by the controller 97. c Take the value of

[0081] The second switch 105 is code S c Based on the value of test1 * and the second inspection torque command value T test2 * Either one of these is used as the torque command value for final inspection T test * The torque command value for final inspection T test * is the final torque command value used to test the reaction motor 12.

[0082] Code S c If the value of is "01", the second switch 105 switches the first inspection torque command value T test1 * The torque command value for final inspection T test * Select as Code S c is "02", the second switch 105 switches the second inspection torque command value T test2 * The torque command value for final inspection T test * Select as Code S cIf the value of is "00", the second switch 105 switches the first inspection torque command value T test1 * or the second inspection torque command value T test2 * The torque command value for final inspection T test * For example, the second switch 105 is selected as code S c The selection state immediately before the value changes from "01" or "02" to "00" is maintained.

[0083] The third switch 106 receives the reaction torque command value T calculated by the reaction torque command value calculation unit 52 as a data input. * and the final inspection torque command value T selected by the second switch 105. test * The third switch 106 also receives as its control input the code S set by the controller 97. c Take the value of

[0084] The third switch 106 is code S c Based on the value of * and the torque command value for final inspection T test * Either one of these is used as the final reaction torque command value T1 * Final reaction torque command value T1 * is the final torque command value used to control the energization of the reaction motor 12. Code S c If the value of is "00", the third switch 106 switches the reaction torque command value T * The final reaction torque command value T1 * The reaction torque command value T * corresponds to the torque command value for driving. Code S c If the value of is "01" or "02", the third switch 106 switches the final inspection torque command value T test * The final reaction torque command value T1 * The power supply control unit 53 selects the final reaction torque command value T1 *Based on this, the power supply to the reaction motor 12 is controlled.

[0085] <Actions and Effects of the Present Embodiment> According to this embodiment, the following actions and effects are achieved. (1) When the control mode is the normal mode, the reaction force control device 1A calculates a torque command value for running suitable for vehicle running as a torque command value to be used by the energization control unit 53. The torque command value for running is the reaction force torque command value T * When the control mode is the inspection mode, the reaction force control device 1A calculates an inspection torque command value suitable for inspection as a torque command value to be used by the energization control unit 53. The inspection torque command value is the first inspection torque command value T test1 * or the second inspection torque command value T test2 * The first inspection torque command value T test1 * or the second inspection torque command value T test2 * is the torque command value for final inspection T test * is selected as.

[0086] That is, when inspecting the steering mechanism 3, the reaction force control device 1A sets the torque command value used by the power supply control unit 53 as the reaction force torque command value T * to the torque command value T for final inspection test * Torque command value for final inspection T test * is calculated to properly inspect the steering mechanism 3, in the same way as when the steering device 2 is an electric power steering device. Therefore, the inspection of the steering mechanism 3 by the inspection device 90 can be properly performed, in the same way as when the steering device 2 is an electric power steering device. In addition, the performance of the product can be properly evaluated.

[0087] (2) When the first inspection is performed, the reaction force control device 1A sets the first inspection torque command value Ttest1 * That is, when the first inspection of the steering mechanism 3 is performed, the reaction force control device 1A calculates the torque command value used by the electrification control unit 53 as the reaction force torque command value T * to the torque command value T for final inspection test * Torque command value for final inspection T test * is the first inspection torque command value T test1 * The first inspection torque command value T test1 * is the steering torque T after dead zone processing h1 Instead, the steering torque T detected through the torque sensor 42 h The assist torque command value T1 is calculated using the following equation. Therefore, the first inspection of the steering mechanism 3 by the inspection device 90 can be performed appropriately, just like when the steering device 2 is an electric power steering device.

[0088] (3) When the second inspection is performed, the reaction force control device 1A sets a second inspection torque command value T suitable for the second inspection as the inspection torque command value. test2 * That is, when the second inspection of the steering mechanism 3 is performed, the reaction force control device 1A calculates the torque command value used by the electrification control unit 53 as the reaction force torque command value T * to the torque command value T for final inspection test * Torque command value for final inspection T test * is the second torque command value for inspection T test2 * The second torque command value for inspection T test2 * is the torque command value T1 to the inspection axial torque T2 test The inspection axial torque T2 is calculated by subtracting test is the hysteresis compensation amount F hys Hysteresis compensation amount F hysis an axial force for compensating for the hysteresis characteristic caused by friction of the steered wheels 6 when the steered wheels 6 are steered. Therefore, the second inspection of the steering mechanism 3 by the inspection device 90 can be carried out appropriately, just as in the case where the steering device 2 is an electric power steering device.

[0089] (4) The first test is a proportional load test in which current is applied to the steering mechanism 3 to check the operability or input / output characteristics of the steering mechanism 3. When the control mode is the test mode, the reaction force control device 1A performs a proportional load test on the steering torque T before the dead band processing is performed. h The assist torque command value T1 calculated based on the test1 * According to this configuration, the proportional load test of the steering mechanism 3 can be carried out appropriately, as in the case where the steering device 2 is an electric power steering device.

[0090] (5) The second test is a torque fluctuation test to check whether the torque fluctuation of the reaction force motor 12 when the steering mechanism 3 is energized and torque is applied to the steering shaft 11 is within the allowable range. When the control mode is the test mode, the reaction force control device 1A calculates the hysteresis compensation amount F hys is converted into a torque for the steering shaft 11, and the inspection axial torque T2 test Furthermore, the reaction force control device 1A calculates the inspection axial force torque T2 from the assist torque command value T1. test The second torque command value for inspection T test2 * According to this configuration, the torque fluctuation inspection of the steering mechanism 3 can be performed appropriately, similarly to the case where the steering device 2 is an electric power steering device.

[0091] (6) The reaction force control device 1A calculates the hysteresis compensation amount F hys Adjust the gain G a The inspection axial torque T2 is obtained by converting the value obtained by multiplying the test Calculate the adjustment gain G ais a fixed value that is set from the viewpoint of appropriately performing a torque fluctuation inspection. According to this configuration, the torque fluctuation inspection of the steering mechanism 3 can be performed more appropriately, as in the case where the steering device 2 is an electric power steering device.

[0092] (7) The reaction force control device 1A switches the control mode from the normal mode to the inspection mode in response to an external command. With this configuration, the control mode can be easily switched from the normal mode to the inspection mode in response to an external command.

[0093] <Other embodiments> This embodiment may be modified as follows. The first switch 101 is code S c Based on the value of h1 and the torque T detected by the torque meter 96. t Either of these is used as the final steering torque T h2 It may be selected as.

[0094] Adjustment gain G a is the hysteresis compensation amount F hys In this case, the converter 103 does not need to multiply the hysteresis compensation amount F hys is converted into a torque for the steering shaft 11, the inspection axial torque T2 test The subtractor 104 calculates the inspection axial force torque T2 calculated by the converter 103 from the assist torque command value T1 calculated by the assist torque command value calculation unit 81. test The second torque command value for inspection T test2 * The multiplier 102 calculates the second inspection torque command value T test2 * Adjust the gain G a By multiplying by , the final second torque command value for inspection T test2 * In this case, the adjustment gain G a is the required final second test torque command value T test2* In order to calculate the torque command value for inspection T test2 * is a coefficient for adjusting

[0095] The test circuit of the reaction force control device 1A may be adapted to only the first test. In this case, the reaction force control device 1A may be configured without the multiplier 102, the converter 103, the subtractor 104, and the second switch 105. The third switch 106 receives the first test torque command value T test1 * The torque command value for final inspection T test * The first torque command value for inspection T test1 * is the assist torque command value T1 calculated by the assist torque command value calculation unit 81.

[0096] The test circuit of the reaction force control device 1A may be adapted to only the second test. In this case, the reaction force control device 1A may be configured without the first switch 101 and the second switch 105. The assist torque command value calculation unit 81 calculates the steering torque T after dead zone processing. h1 The third switch 106 receives the second torque command value for inspection T test2 * The torque command value for final inspection T test * Import as. [Explanation of symbols]

[0097] 1...Steering control device 1A...Reaction force control device (reaction force control unit) 2...Steering device 3...Steering mechanism 5...Steering wheel 6...Steering wheel 12...Reaction motor 22...Steering shaft 42...Torque sensor

Claims

1. A steering control device configured to control a steering device in which power transmission between steered wheels of a vehicle and a steering wheel is separated, the steering device having a steering mechanism including a reaction motor configured to generate a steering reaction force to be applied to the steering wheel, a reaction force control unit configured to control the reaction force motor based on a torque command value calculated in accordance with a steering state of the steering wheel, the reaction force control unit has, as control modes for controlling the reaction force motor, a normal mode for running the vehicle and an inspection mode for inspecting the steering mechanism, when the control mode is the normal mode, the reaction force control unit calculates, as the torque command value, a driving torque command value suitable for driving the vehicle; The steering control device is configured to calculate, when the control mode is the inspection mode, an inspection torque command value suitable for the inspection as the torque command value.

2. the inspection includes a first inspection and a second inspection; the reaction force control unit calculates a first inspection torque command value suitable for the first inspection as the inspection torque command value when the first inspection is performed, 2. The steering control device according to claim 1, wherein when the second inspection is performed, a second inspection torque command value suitable for the second inspection is used as the inspection torque command value.

3. the inspection includes a proportional load test for energizing the steering mechanism to check the operability or input / output characteristics of the steering mechanism, the reaction force control unit performs a dead zone process in which, when a value of the steering torque detected by a torque sensor mounted on the vehicle is within a dead zone range, the value of the steering torque is replaced with zero; a process of calculating an assist torque command value, which is a torque in the same direction as the steering direction of the steering wheel, based on the steering torque after the dead zone process has been performed; a process of calculating an axial force acting on a steering shaft that steers the steered wheels based on a steering state of the steered wheels, and converting the calculated axial force into a torque applied to the steering wheel to calculate an axial force torque; and calculating the torque command value by subtracting the axial force torque from the assist torque command value, 3. The steering control device according to claim 1, wherein the reaction force control unit is configured to use, when the control mode is the inspection mode, the assist torque command value calculated based on the steering torque before the dead zone processing is performed as the inspection torque command value.

4. the inspection includes a torque fluctuation inspection for checking whether torque fluctuation of the reaction motor when a torque is applied to a steering shaft by energizing the steering mechanism is within an allowable range; the reaction force control unit performs a dead zone process in which, when a value of the steering torque detected by a torque sensor mounted on the vehicle is within a dead zone range, the value of the steering torque is replaced with zero; a process of calculating an assist torque command value, which is a torque in the same direction as the steering direction of the steering wheel, based on the steering torque after the dead zone process has been performed; a process of calculating an axial force acting on a steering shaft that steers the steered wheels based on a steering state of the steered wheels, and converting the calculated axial force into a torque applied to the steering wheel to calculate an axial force torque; and calculating the torque command value by subtracting the axial force torque from the assist torque command value, the axial force includes a hysteresis compensation amount calculated based on a steering angle of the steering wheel, the hysteresis compensation amount being an axial force for compensating for a hysteresis characteristic caused by friction of the steered wheels, 3. The steering control device according to claim 1, wherein, when the control mode is the inspection mode, the reaction force control unit converts the hysteresis compensation amount into a torque for the steering shaft to calculate an inspection axial force torque, and calculates the inspection torque command value by subtracting the inspection axial force torque from the assist torque command value.

5. the reaction force control unit is configured to calculate the inspection axial force torque by converting a value obtained by multiplying the hysteresis compensation amount by an adjustment gain into a torque applied to the steering shaft, The steering control device according to claim 4 , wherein the adjustment gain is a fixed value that is set from the viewpoint of appropriately performing the torque fluctuation inspection.

6. 3. The steering control device according to claim 1, wherein the reaction force control unit is configured to switch the control mode from the normal mode to the inspection mode in response to an external command.

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